There is an excellent post over on the Word team blog that goes into details on how the new content controls feature (when parred with XML mapping) allows for powerful data-view separation in you wordprocessing documents. I've talked many times about the custom defined schema support, and this post from Tristan does a great job of explaining how that can be achieved.
If you want to see a couple quick demos, a few months back I posted some videos on Channel 9 that helped show what you could do with this.
Tristan actually had a series of posts on this subject, most of which focused on the non-XML side of content controls. This last post is his first to touch on the XML mapping functionality. There will be more posts to come that show how document management systems like SharePoint can allow you to view and modify the custom data without actually editing the presentation of the file. Here are all of Tristan's current posts in order: